Three dimensional viewing apparatus



June 1, 1965 w. A. CLAY 3,187,339

THREE DIMENSIONAL VIEWING APPARATUS Filed Oct. 16. 1961 4 Sheets-Sheet 1IN VE NTOR VVilllaceACla /y W. A. CLAY THREE DIMENSIONAL VIEWINGAPPARATUS 4 Sheets-Sheet 2 FIG.

INVENTOR. WALLACE A. CLAY June 1, 1965 Filed Oct. 16. 1961 D A F n F aCE C June 1, 1965 w. A. CLAY THREE DIMENSIONAL VIEWING APPARATUS 4Sheets-Sheet 3 Filed Oct. 16. 1961 INVENTOR Walla ceALZ y THREEDIMENSIONAL VIEWING APPARATUS 4 Sheets-Sheet 4 Filed Oct. 16, 1961INVENTOR g3 Q Walla/0e A. Glad I United States Patent 3,187,339 THREEDIMENSIONAL VIEWING APPARATUS Wallace A. Clay, Box 1'26, RED. 3, Ogden,Utah Filed Oct. 16, 1961, Ser. No. 145,058 6 Gaims. (Cl. 35261) This isa continuation-in-part of United States patent application by the sameinventor and of the same title, Serial No. 422,542, filed April 12,1954, which is now abandoned.

My invention relates to 3-dimensional photography; and more specificallyprovides a method and apparatus for photographing and subsequentlyreproducing a series of stereoscopically related views on anexhibition-size screen in such a way that the composite etlect of saidviews appears to an audience as a 3-dimensional panoramic scene.

The principal object of my invention is to provide a photographic methodand apparatus by which either still or motion pictures may bephotographed and subsequently reproduced by projection on a specialscreen, or by which still pictures may be reproduced by arrangement ofdistorted prints or transparencies behind a special screen, the saidimages appearing S-dimensional to an audience without the necessity ofpersonal apppendages of any kind.

My method involves the use of a plurality of cameras which for practicalpurposes are preferably mounted on the same dolly, the optical systemsof the various cameras facing in the general direction of the scene tobe photographed and their centers being mutually spaced an equaldistance apart. While for rather close-up scenes they may be parallel,for distant scenes the camera axes will be divergent so that adjacentcamera axes subtend a desired stereoscopic angle in the range of from 4down to 5", but generally of the order of 2, an accepted stereoscopicangle value. Each of these camera units photographs a portion of thescene, the pictures taken by adjacent cameras overlap considerably as tosubject matter, and each picture forms with an adjacent picture astereoscopic doublet.

In order that a composite of all of the pictures taken may be panoramic,i.e. cover a wide angle, the axes of each of the respective cameras areadjusted either mutually parallel, or else somewhat divergent. Theindividual sequences of pictures taken by the respective cameras arethen projected onto a specially constructed screen by a bank oftransversely spaced projectors, in the elementary form of the inventionone projector being used for each camera which was used in taking'thepictures, OR, in a more advanced form of the invention, a lesser numberof projectors than cameras being used and each projector projecting aplurality of adjacent pictures from a com posite film.

My screen is a composition of a number of horizontally-adjacent viewingcells each of which is a vertically elongated box having an objectivesurface at its rear onto which a picture is projected or otherwisedisposed or atfixed, and having at its front a vertically elongated lensthrough which the audience views the picture. The pictures disposed uponthe scenes of adjacent objective surfaces of adjacent viewing cellscorrespond in their progression as to relative disposition to theprogression of the regularly stepped cameras heretofore mentioned.Screens of a somewhat similar type are not unknown in the prior art.

My invention differs from other approaches in that in my invention inits elementary form each of the individual projectors, if employed,projects its picture on the back objective surface of only one viewingcell, whereas in other approahces to the problem, each projector casts acomplete scene, elements of which are impinged on each of the viewingcells.

As stated above, all of the pictures taken by the respective adjacentcameras overlap to a considerable extent With respect to the subjectmatter photographed. According to my method, each of the pictures thusphotographed may subsequently be distorted, i.e. either compressedhorizontally or stretched vertically, so that it may be projected ontothe back objective surface of a single viewing cell in its entirety. Thevertical stretching of the respective pictures may, of course, beaccomplished in any desired manner, i.e., the pictures may be stretchedvertically or compressed horizontally after they are photographed andbefore they are projected, or else the cameras and projectors may beequipped with proper lenses for vertically stretching or horizontallycompressing the pictures automatically either as they are taken or asthey are projected, so as to produce the elongation required and permitthe picture to be projected in its entirety onto the back objectivesurface of a single viewing cell. The center of each of these viewingcells is spaced from the center of each immediately adjacent viewingcell by a selected value of spacing, as may be arbitrarily determined,and each cell will be as high as is desired for the height of theparticular exhibition screen, which screen is the composite of all saidviewing cells.

If, therefore, we assume that the entire scene has been protographed bysaid plurality of cameras and that the resulting pictures have beenvertically stretched or horizontally compressed and each projected onthe back objective surface of a viewing cell, it should then be apparentthat before the composite scene may be viewed by the audience it will benecessary to restore each projected picture {c.g.) to its originalvertical-to-horizontal proportion. In other words, having stretched thepictures and having caused them to fit the back objective surface of avertical screen element, it is then necessary to provide means wherebythe pictures may be unstretched so that they will have a naturalappearance. The unstretching of these pictures is accomplished by thelens elements which form the fronts of the viewing cells, which lenselements are anamorphoscopic and may be double convex lenses when viewedin horizontal cross section only and vertically elongated to the fullheight of the viewing cells.

When a single viewing cell is viewed by one eye from the audience sidethereof, the observer will see through the lens of said viewing cell arelatively narrow vertical strip, the selection of which depends uponthe position of the observer with respect to the viewing cell, of thepicture, which vertical strip will be horizontally magnified by the lensto its original horizontal-to-vertical proportions in such a way thatthe magnified image of the vertical strip will appear to be the fullwidth of the lens and therefore the full width of the viewing cell asseen by the audience. If the respective distorted (i.e. verticallystretched or horizontally compressed) pictures are properly oriented inprogressive, side-by-side relationship on the back objective surfaces ofthe viewing cells, the magnified strip portions of all the pictures seenby one eye at a particular viewing point in the audience will blendtogether so as to form a single, composite, panoramic picturecorresponding to substantially the entire scene pho tographed. Theremaining eye will also see a single, composite, panoramic scene,similar to the previously mentioned panoramic scene, with correspondingportions of both of said panoramic scenes being stereoscopic doublets.

An important advantage of my system over the prior art systems is thatWhile in each case the foreground portion of the pictures may be quiteclear, the background 3 portion of some of the prior art pictures tendsto be blurred due to the fact that the background as seen in any singleviewing cell is a composite of elements projected by all of theindividual projectors converging from different angles. Clarity of theforeground and lack of importance of sharp background render such priorart systems suitable for portraits and close-up work but not forpanoramas. The background of the pictures shown according to my systemis clear since on each viewing 'cell the entire background wasphotographed by a single camera from a single viewing point, therebyaccommodating panorama work.

-In many of the prior art systems the individual cameras secured to thecamera dolly are adjusted so that the axes of their'opt'ical systemsconverge in the direction of the object to be photographed. According tomy method, however, the cameras are set either mutually parallel or areset so that. they diverge somewhat. The advantage of this divergence ofthe cameras instead of convergence is that a much larger field iscovered, and when these pictures are projected upon the screen, which isconcave on the audience side, the scene takes on a panoramic effect,thereby permitting the audience not only to see the entire scene instereoscopic relief but also to enjoy a much wider,

field of vision. As to degree of concavity of the viewing screen, thesame will usually be equivalent to the degree of diver-gency of 'thecamera position pattern, although, for certain special effects, slightvariation from equivalency may be made.

Another important advantage of using a screen which is concave whenviewed from the audience side is that the individual elements formingthe composite screen may be adjusted so that the entire screen isvisible from any point within the general viewing area but so thatsubstantially the entire screen blacks out simultaneously as theobserver moves outside the generalviewing area which the screen isdesigned to serve.

The foregoing description specifies a separate projector for each cameraand each corresponding viewing cell. However, in practice a lessernumber of projectors would probably be used in which event eachprojector would cast a plurality of images taken by adjacent cameras,the said images being arranged side-by-side on a composite projectionfilm and the said images each being cast on separate adjacent viewingcells. This simplification of the projection system might go so far asto require only a single projector, especially where a relatively smallcomposite screen is used. In the case of larger composite screens,several projectors would probably be used and their respectiveprojections grouped to serve the several adjacent portions of thescreen.

As suggested in the above objects, the viewing cells need not be madethe same width as said interocular spacing but may be varied directly inaccordance with the distance of the audience from the screen. However,each lens should preferably subtend an angle of the order of 2" withrespect to the observers eye.

The pictures need not be projected on the back objective surfaces of theviewing cells, but maybe stretched and printed and placed behind theanamorphoscopic lenses to form a 'still stereoscopic exhibition that maybe used in store window displays, etc.

I will now explain my invention with reference to the drawings whichshow practical embodiments of my apparatus wherein:

\FIGURE 1 is a schematic plan view of a projection system according tomy invention, showing the individual pictures projected on the rearobjective surfaces of the veiwing cells of the screen and showing theeyes of an observer located on the opposite, or concave, side of thescreen.

FIGURE 1A. is- (an enlarged detail and schematic diagram, rotated 90 ina counter-clockwise direction, of a portion of the structure of FIGURE 1and of the optical phenomena which are therein operative, by virtue ofthe structure disclosed, to produce a stereoscopically viewablepanoramic scene.

FIGURE 2 is an enlarged horizontal section through one of the viewingcells showing a complete single picture projected on the rear objectivesurface of the cell and indicating two separate portions of the picturewhich will be seen from two different viewing points on the audienceside of the screen.

FIGURE 3 is a front elevation view of the composite screen.

FIGURE 4 is a sectional plan view looking down on a plurality ofprojectors, each casting an image on the back objective surface of anassociated viewing cell of the screen. In this form of my apparatus theaudience views the pictures on the opposite side of the screen from theprojectors.

FIGURE 5 is an enlarged sectional view of a viewing cell which issimilar to the viewing cell shown in FIGURE 2 but which is modified toshow a stretched positive print forming the back objective surface ofthe viewing cell, this type of viewing cell being used when my inventionserves to provide a non-projection type still exhibition having3-dimensional panoramic characteristics.

FIGURE 6 shows the stretching of a picture so as to elongate the picturesufiiciently to fit the back objective surface of a viewing cell.

FIGURE 7 is a plan view of a camera dolly showing a single cameramovably mounted on the dolly for photographing progressively successiveportions of the whole panoramic scene for non-projection typeexhibition.

FIGURE 7A is a plan view of a camera dolly having a plurality ofdivergently arranged cameras, some being shown schematically in phantomlines for convenience of illustration, fixedly mounted thereon forphotographing progressively, and preferably simultaneously successiveportions of the whole panoramic scene for non-projection typeexhibition.

Referring now to the drawings, FIGURE 1 shows an arcuate series ofprojectors 1 located behind a projection screen 2, the series ofprojectors comprising a plurality of individual projection machines 1aeach one of which includes, as shown in FIGURE 4, a lens system system1b located beyond a light source (not shown) and a film F. 1f theapparatus is to be used for showing motion pictures, each projectorwould also include a film-feeding mechanism which may be of anyconventional type, the individual film-feeding mechanisms of theprojectors being all linked together for unitary actuation so as tomaintain the projectors synchronized. If the system is to be used forshowing slides or other still pictures, then the apparatus shown inFIGURE 4 would include only a light source (not shown), the film F andthe lens system 1b. In addition, in order to prevent interference of thelight projected by the respective projectors 1a, the latter may beprovided with a system of shields 1c.

The screen 2 includes a plurality of vertically oriented elongatedviewing cells 2a, FIGURE 3, the number of viewing cells being the sameas the number of projectors Ia for the purpose hereinafter stated.FIGURE 2 shows in cross-section one embodiment of a viewing cell whichcomprises a pair of opposed frame members 2b which are maintainedseparated in fixed, spaced relationship by an anamorphoscopic lenselement 2d and by a translucent rear objective screenelement 2c, thelatter having a translucent, projected image receiving projectionsurf-ace 2c comprising an etched or otherwise treated or painted surfaceon either side of element 20. Each of the frame members 2b has asemi-circular recess 22 adapted to receive a rod 3, as shown in FIGURE4, which rods serve to pin the individual viewing cells together for thepurpose of forming a composite screen, as shown in front elevation inFIGURE 3.

As shown in FIGURES 1 and 4, each viewing cell is slightly wider at therear than it is at the front, so that when all of these viewing cellsare assembled to form a composite screen, the screen will be concave onthe audience side.

One form of camera means 4, as shown in FIGURE 7, may also include anarm 40 pivoted at one end to the dolly 4a as at 4d. The other end of thearm 40 carries a single camera 4e with which individual photographs maybe taken at any one of the several successive camera positions 4b thearm 40 being swung back and forth to any desired position within therange of the fixed camera posi- *tion 41) by a suitable pulley and cablemechanism 4- and the dolly being curved to provide the chosen divergenceof the bank of camera positions 412.

Of course, one may fixedly mount a series of cameras in camera positions4b in lieu of employing a single, movable camera 4e as shown. Thus, inFIGURE 7A is illustrated camera means 4 which include a dolly 4a adaptedto support a plurality of fixedly disposed cameras 412. The cameras maybe of any conventional type and, if the system is to be used forproducing motion pictures, the filmfeeding mechanisms of the cameraswill all be synchronized (not shown). In any event the camera means usedis adapted to take exposures from a regularly divergent pattern ofcamera exposure orientations adjacent ones of which mutually diverge, asherein explained, a stereoscopic angle of the order of 2, i.e. from to4.

As to camera positioning as is illustrated in FIGURES 7 and 7A, it is tobe noted that the camera pattern is divergent outwardly. This divergencyenables one to take a wide-angle panorama with a finite number ofsuccessively stepped exposures of successively overlapping subjectmatter, and taken either simultaneously or sequentially. Secondly, thedivergent camera pattermit follows, spaces adjacent camera positions.Where this spacing between adjacent lens positions of the camera meansis equivalent to average, human inter-ocular spacing, ie 2% inches, thenreproductions of adjacently taken exposures of a close scene, whenviewed individually by the respective eyes of the observer, will producea stereoscopic effect.

However, for panoramic scenes in nature, inter-cameraaxis spacing isrelegated to less importance, whereas the angle of divergency betweenadjacent camera position axes becomes of prominent importance for, forgreater distances, divergency angle alone and without consideration ofinter-camera-position spacing will produce a desired stereoscopic effectover and above that experienced by a viewer viewing binocularly apanoramic scene, provided this divergency angle is maintained withinreasonable limits, ie from 4 to 5", which range will be consideredherein as of the order of 2. (It will be remembered that 2 is theaccepted value of the stereoscopic angle, i.e. the angle, subtended bythe eyes of the observer relative to a fixed point on an observedobject. The 2 figure is generally agreed upon as the angle at whichgreatest stereoscopic eifect is realized; howbeit the eyes mightaccommodate an angle as high as 4, with the stereoscopic eifectdecreasing as the distance between observed object and the observer isincreased until, for angles less than 5", practically no stereoscopiceffect will be discernable. This stereoscopic angle is an angle ofconvergence. The stereoscopic angle of divergence relating to adjacentcamera positions not only produces a series of displaced cameraexposures, reproductions of which may be placed side-by-side toillustrate a panorama, but also insures that corresponding elementalareas of adjacent reproductions, while of the same subject matter, maybe viewed stereoscopically since the exposures thereof where taken fromdifferent, stereoscopically related camera positions and since,therefore, there will be a shift in foreground relativeto background asone proceeds from left to right, as is also the case in convergentsystems.)

:In FIGURE 7A the angle 0 between adjacent camera axes A and A is thedivergency angle above spoken of and in magnitude is of the order of 2,the actual 2 figure being preferable but the range 4-5" beingacceptable.

6 Method of operation My method is carried out by an apparatus, such ashas been described, in the following manner:

The cameras 4b in FIGURE 7A, for example, photograph preferably insynchronism, a plurality of progressively related, panoramic sectorswhich overlap as to subject matter, the individual photographs made byadjacent cameras being mutually related as stereoscopic doublets. Inother words, the subject matter photographed by adjacent cameras dboverlap so that each individual picture is similar to each adjacentpicture except that it was photographed from a view-point separated fromthe point from which the adjacent photograph was made by a suificientdistance to establish a definite stereoscopic relationship with thecamera position on either side of it. Thus, inter-camera distance willbe equal to the chord length of the stereoscopic angle desired (i.e. ofthe order of 2) at a radius equivalent to the radius of curvature of thedivergent camera pattern. For example, where the radius of curvature ofthe divergent camera pattern is 7 feet then, for a stereoscopic angle of2 the inter-camera distance will be approximately 2.5 inches. Althoughthe cameras 4b are shown to be more or less convexly (i.e. divergently)arranged, the degree of divergence shown in FIGURE 7A is exaggerated,and the cameras actually may be arranged either in mutually parallelrelation or may be arranged to diverge a selected degree. Actually, acertain amount of divergence of the individual cameras is desirable inorder that the individual pictures when projected onto a compositescreen of reasonable dimensions may reproduce a panoramic viewencompassing a fairly wide angle. With respect to this feature, mymethod differs from pior art methods since in most prior art methods theindividual cameras are arranged in concave orientation so that theiraxes tend to converge at or near the particular object beingphotographed; while such is suited for close-ups and portraits, the sameis not suitable for panoramas because of the comparatively narrowviewing angle and confused background which necessarily result.

FIGURE 6 illustrates two pictures 5 and 51: respectively. The picture 5represents a single photograph which might be taken by a single camera(or 412), the relative proportions of the subject matter in the picture5 being to proper scale. The picture 5a, however, has been verticallystretched so that the relative ratio of height to width of the pictureis the same as the ratio of height to width of a back objective element2c of a viewing cell 211. The stretching of the picture 5 so as toassume the distorted proportion shown at St: (an image anamorphosis) inFIGURE 6 may be accomplished by any desired means. For example, thelenses on each individual projector 1:: may be ground so as toautomatically stretch the picture 5 to the form shown at 5:1.Alternatively, the films made by the cameras 45 might be run through astretch-printer so designed that a negative having the proportions shownat 5, when printed or transposed onto positive film, would have theproportions shown at 5a.

The term image anamorphosis as used throughout shall be understood tocomprise a photographic object such as a print, transparency, and soforth, wherein the horizontal dimension of the subject matter thereof,as at 5:2 in FIGURE 6, is compressed relative to the vertical dimensionof the subject matter.

Regardless of how the stretching of the picture 5 is accomplished, thepicture projected by a projector 1a onto the back objective surface 2cof a viewing cell 2a will have such proportions that it will fallentirely upon a single projection surface 20' of the appropriate viewingcell 211.

By reference to FIGURE 2 it will be seen that the viewing cell 211receives picture 5a '(see FIGURE 6) on the translucent projectionsurface 20 of the cell, and that if the lens 2d were removed from thefront of this viewing cell 2a, an observer sitting on the audience sideof the cell would see the picture exactly as shown in FIGURE 6 at Sat,i.e., distorted. However, the lens element Ed is anamorphoscopic and isso designed that it horizontally magnifies only a relatively narrowvertical strip of the picture a. Therefore, a viewer sitting directly infront of the viewing cell 2a, shown in FIGURE 2, would see a verticalstrip x of the picture magnified to the width x, and an observer sittingto the right of the viewing cell 2a would see a vertical element y ofthe picture 5a magnified to the width y. Note that in each of the casesdescribed above, the observer is assumed to be looking at the viewingcell 2a with only one eye.

However, by reference to FIGURE 1 wherein is shown an observer havingtwo eyes, namely a left eye E and a right eye E, it will be seen byfollowing the dashed lines extending outwardly from each of said eyesthat the left eye E looks into one particular viewing cell and that theassociated right eye E looks int-o the next adjacent viewing celllocated immediately to the right.

From the above discussion it should be apparent that each respective eyeof an observer views only a narrow vertical element of a picture 5a, andthat if the pictures are properly oriented on the back objectivesurfaces of the respective viewing cells, the narrow vertical strip ofone picture So as seen by an observers right eye will be a stereoscopicdoublet with respect to the narrow vertical strip of another picture .asseen by the observers left eye, the pictures being magnified by theanamorphoscopic lenses on the respective viewing cells. With the lenselements properly designed on the cameras, projectors and viewing cells,and with the viewing cells properly oriented with respect to each otherto form a properly designed composite screen, every observer within theviewing range of the screen will see a continuous picture across thefull width of the screen with his right eye and will see a dif ferentcontinuous picture with his left eye, the two pictures beingstereoscopically related.

We shall now consider the phenomenon which takes place in detail.Reference is now made to FIGURE 1A wherein a portion of the screen ofFIGURE 1 is enlarged and shown in detail, and wherein the optical linesfrom the eyes E and E of the observer are drawn for purposes ofunderstanding the invention.

It will be remembered that the camera structure of either FIGURE 7 orFIGURE 7A may be employed to take a progressive series of exposures of apanorama, with the exposures overlapping as to subject matter. if theconventionally established stereoscopic angle of 2 is agreed upon, i.e.the angle at which maximum stereoscopic effect is obtained, then, if theradius of curvature of the camera pattern is seven feet, for example,then adjacent camera position will be, with respect to their respectiveoptical axes, about 2 /2 inches apart. Obviously, where the radius ofcurvature of the camera pattern varies from a 7-foot figure, then theinter-camera position facing will also vary, this variation being such,preferably, that the selected stereoscopic angle between adjacent camerapositions, be maintained. In any event, the projectors la in FIGURE 1may be supplied transparencies (or developed prints may be used as shownin FIGURE 2) such that the objective screen surf-ace elements 20 mayhave projected or otherwise disposed thereon respective scene sectors,with adjacent scene sectors being stepped progressively according to thecamera patter-n aforementioned, and with a respective print or projectedscene being disposed upon a respective one of the screen elements 20.

In continuing our reference to FIGURE 7A, for example, we shall assumethat a panoramic scene is being photographed, i.e. the camera film, ofthe several cameras (or the one camera of FIGURE 7) is exposed so thatat camera positions C1, 02., and C3, progressively, respective exposures01, C2, C3, etc. will be taken. In other Words, a regularly progressiveplurality of pictures C1, C2, C3, etc., comprising image anamorphoses,of overlapping scene sectors of the scene photographed will have beentaken. Adjacent ones of the exposures may be considered as stereoscopicdoublets since angular displacement between adjacent camera positions isof the order of 2 -(-i.e. within the range of 4-5). The projectors 1A inFIGURE 1 will respectively project respective ones of said scenes in thesame order so these scenes 01, C2, and C3, corresponding to the camerapositions C1, C2, and C3, will be disposed upon the surfaces 20' ofadjacent objective screen elements 2c. Of course, rather than usingprojector apparatus, as in FIGURE 1, the individual reproductions inform of transparencies or prints may be disposed on the objectiveelement 20 as in FIGURE 5 at 2].

The reproductions (either by projection or by physical indicia) C1, C2,and C3, which constitute image anamorphoses of the scene sectorsphotographed maybe thought of as being comprised of a progressive seriesof vertical strips (see FIGURE 1A) with the strips C in thereproductions being identical subject matter, the strips D beingadjacent but identical subject matter, and so torth. In other words, thevertical strip sector A in 01 corresponds to a portion of the subjectmatter taken by a camera in position C]. (see FIGURE 7A) but whichsubject matter portion does not appear in any of the subsequently takenexposures. not appear is because the camera has been displacedprogressively in one direction so as to leave area A out of subsequentexposures. However, as in the example shown in FIGURE 1A, subject matterB in reproduction Cl, taken in camera position 01, will also be seen atvertical strip area B of reproduction C2 corresponding to cameraposition C2. The subject matter of the vertical strip areas of the sameletter, e.g. B, of the reproductions are identical as to subject matter,but are stereoscopically related, since the exposures from which thereproductions are produced, were taken from displaced vantage pointsalong stereoscopically displaced camera axes.

Where the focal lengths (which are equal) of the lenses 2d (e.g. 5.5inches) are greater than the (equal) distances (e.g. 4 inches) betweenthe lenses and the image receiving surfaces, then the vertical striparea C at reproduction Cl will be seen by the right eye E, but verticalstrip area.

D and not area C (except possibly for a slight, permissible overlappingfringe) will be seen by the left eye E. On reproduction 02, verticalstrip area D will be seen by the right eye E and strip E seen by theleft eye. These elemental vertical strip areas are magnified as virtualimages bythe respective lenses M1, M2, 2x23, and 2a to the full width ofthe individual lenses.

As to the left eye E, this eye will see vertical strip area D inreproduction C1, verticalstrip area B in repro duction CZ, verticalstrip area F in reproduction C3, etc. Thus, the left eye will see thesevertical strips and subsequent ones, which will be magnifiedhorizontally by the respective lenses 2d(1), 2d(2), 2:1(3), and 2d(4) soas to present a blended panorama viewable by the left eye.Correspondingly, the right eye B will see strip C in reproduction 01, Din C2, E in C3 and so on, the strips being magnified by their respectivelenses to the width of the lenses to produce a second panorama. It willbe noted that these two panoramas will be substantially the same incharacter;.howbeit, cor-responding portions (i.e. magnifiedcorresponding vertical strips) of the two panoramas will be stereoscopicdoublets, again by virtue of the different vantage points (see above)from which the exposures resulting in thereproductions were taken.

Where the focal length of the individual lenses, 211(1), 2d(2), 211(3),and 2d(4), are equivalent to 5 /2 inches, for example, and the distancebetween these lenses and their respective objective screen segments 20equivalent to 4 inches, approximately, then, not only will the magnifiedvirtual images produced enable the blending in of the panoramas beefiectuated, but also the refraction of the individual lenses will besuch that the optical ray lines. of adjacent vertical segments of arespective reproduction The reason that it does will cross and .be seenby the respective eyes so that when both eyes are looking through asingle lens, the right eye will not see any portion (save for a slightpermissible fringe juncture, to be kept to a minimum) of what the lefteye sees, but rather will see a vertical strip area which is adjacentand crossed over with respect thereto. In this manner, the need for .aphysical septum between the eyes so as to obtain a stereoscopic efiectis not needed. What is focused upon the retinas of the two eyes are tworespective individual, blended in panoramas (one for each eye)corresponding portions of which are stereoscopicaliy related asstereoscopic doublets.

As to the width of the viewing cells for minimum distortion, theseshould preferably be such that the same should subtend an angle, wit-hrespect to one eye of the observer, which is equivalent to thedivergence angle of the camera pattern. Thus, the radius of curvature ofthe camera pattern should equal the nominal or average distance ofobservation from the screen. The projector pattern of FIGURE 1 should beequivalent in degree of convergence to the degree of divergence of thecamera pattern. The nominal arcs the viewing cells 2a and pro- "ectors1a will have a common center spaced from the screen 2, again, a distanceequal to the radius of curvature of the camera pattern. Again, for leastdistortion the objective screen segments 20 and their projectionsurfaces 2c should be concave, having a center point of curvature at theoptical center of the lines 2d with which they are associated.

Referring again to FIGURE 1, the point C near the lower end of thefigure represents the location of the centers of the cameras when thecomposite scene was photographed. Thus it will be seen that the axes ofeach individual camera 41;, of each associated viewing cell 2a and ofeach associated projector 1a are all in alignment. When such axes areall in alignment the entire system is said to be in tight formation.However, since it is desirable that the system be capable of serving aslarge an audience as possible, it has, by experiment, been foundpossible to rotate each of the viewing cells through a small angle insuch a direct-ion that the axes of each viewing cell 251 may be causedto intersect at a point B located further out on the center line of thesystem than point C, as shown at the bottom of FIGURE 1.

When the individual viewing cells have been thus realigned so as to besomewhat less convergent toward the audience, the individual screenelements are said to be in loose formation. Theoretically, repositioningthe axes of said viewing cell to loose formation will introduce an errorinto the pictures as seen by the audience. However, experimentation hasshown that considerable benefit can be realized by setting the viewingcells in loose adjustment because the size of the audience may beconsiderably increased thereby; and it has also been found by experimentthat through relatively small changes of angle (changes from tight toloose formation) the error is not perceptible to the audience, andtherefore the loose formation appears to be more satisfactory on apractical basis than the tight formation.

The modification shown in FIGURE 5 is made for the purpose of exhibitingstereoscopic still pictures and includes a plurality of viewing cells 2each having an anarnorphoscopic lens 2d on the audience side and eachcell having as a back-objective surface a stretched positive print 2gwith the emulsion side 2f thereof facing toward the lens 2d. This typeof exhibition i especially suitable for advertising in stores and storewindows, and the composite screen may be produced in any size desired.

Other changes and modifications in the apparatu shown in the respectivefigures are possible within the scope of the following method andapparatus claims.

I claim:

1. Apparatus for reproducing on a viewing screen, before an audience,and in stereoscopic relief, a scene employing a progressive series ofstereoscopically related pictures adjacent ones of which arestereoscopic doublets, said apparatus comprising: a composite contiguousviewing screen including a horizontal series of viewing cells each havnga back, projected image receiving projection surface and a front lens inlight communication therewith and spaced therefrom a distance less thanthe focal length of the lens, the respective distances between theindividual lenses and their respective projection surfaces beingequivalent, and the widths of the respective viewing cells being equal;a plurality of horizontally spaced projector means each directed solelytoward the projection surface of a single associated cell to castthereon a respective one of a regularly progressive plurality ofpictures of overlapping scene-sectors of a scene photographed, saidfront lenses being anamorphoscopic to magnify horizontally, selectedvertical strips of said pictures, selection being determined by theposition of the observer; and means for distorting thevertical-to-horizontal proportions of the pictures prior to casting themonto the projection surfaces to compensate for the horizontalmagnification of said lenses, said lenses being so constructed and soarranged, of them-selves and with repect to their repective, projectedimage receiving projection surfaces, that from each viewing angle in theaudience there will be seen by the respective eyes of an observerthrough each front lens respective images which are coextensive in anglesubtended with said lens, with respect to said respective eyes, andwhich correspond to adjacent ones of said narrow vertical strips of eachdistorted picture but are magnifled horizontally to restore the originalproportions thereof, and that said images as seen through all the lensescombine and blend together in two independent series, seen by therespective eyes, to produce two, independent, composite scenes, eachviewable by a single eye, corresponding portions of said compositescenes being stereoscopically related.

2. Apparatus as set forth in claim 1 wherein said projector meanscomprise synchronized motion picture machine means.

3. Apparatus for reproducing on a viewing screen, before an audience,and in stereoscopic relief, a panoramic scene employing a progressiveseries of stereoscopically related pictures adjacent ones of which arestereoscopic doublets, said pictures being taken divergently outwardlytoward the panoramic scene, said apparatus comprising: a compositeviewing screen including a horizontal series of contiguous viewing cellscompositely arcuate in degree corresponding to the degree of divergenceat which the progressive series of pictures were taken, each viewingcell having a back, projected image receiving projection surface and afront lens in light communication therewith and spaced therefrom adistance less than the focal length of the lens, the respectivedistances between the individual lenses and'their respective projectionsurfaces being equivalent, and the widths of t e respective viewingcells being equal; horizontally spaced projector means directed towardthe projection surfaces of said associated cells to cast, solely uponcorresponding ones only of said cells, successive ones of a plurality ofpictures taken of said panoramic scene from a regularly divergentpattern of exposure orientations adjacent ones of which mutually divergetoward said scene a stereoscopic angle of a magnitude of the order of 2,said front lenses being anamorphoscopic to magnify horizontally,selected vertical strips of said pictures, selection being determined bythe position of the observer; and means for distorting thevertical-to-horiz-ontal proportions of the pictures prior to castingthem onto the projection surfaces to compensate for the horizontalmagnification of said lenses, said lenses being so constructed and soarranged, of themselves and with respect to their respective, projectedimage receiving surfaces, that from each viewing angle in the audiencethere will be seen by the respective eyes of an observer through eachfront lens respective images which are coextensive in angle subtendedwith said lens, with respect to said respective eyes, and whichcorrespond to adjacent ones of said narrow vertical strips of eachdistorted picture but are magnified horizontally to restore the originalproportions thereof, and that said images as seen through all the lensescombine and blend together in two independent series, seen by therespective eyes, to produce two, independent, composite scenes, eachviewable by a single eye, corresponding portions of said compositescenes being stereoscopically related.

4'. Appanatus for reproducing on a viewing screen, before an audience,and in stereoscopic relief, a scene employing a progressive series ofstereoscopically related pictures adjacent ones of which arestereoscopic doublets, said apparatus comprising: a composite viewingscreen including a horizontal series of contiguously disposed lenses andprojected image receiving surface mean disposed rearwardly of saidlenses at a distance less than the focal lengths thereof, said lenseshaving equivalent focal lengths and equivalent widths; a plurality ofhorizontally spaced projector means each directed toward a portion ofsaid image receiving surface means in registry with a respective one ofsaid lenses to cast thereon, a respective one of a plurality of picturestaken of said panoramic scene from a regularly divergent pattern ofexposure orientations adjacent ones of which mutually diverge towardsaid scene a stereoscopic angle of a magnitude of the order of 2, eachof the series of pictures being in respective registry with a respectiveone of said lenses, said lenses being anamorphoscopic to magnify,horizontally, selected vertical strips of said pictures, selection beingdetermined by the position of the observer; and means for distorting thevertical-to-horizontal proportions of the pictures prior to casting themonto the image receiving surface means to compensate for th horizontalmagnification of said lenses, said lenses being so constructed and soarranged, of themselves and with respect to said image receiving surfacemeans, that from each viewing angle in the audience there will be seenby the respective eyes of an observer through each of said lensesrespective images which are coextensive in angle subtended with saidlens, with respect to said respective eyes, and which correspond toadjacent ones of said narrow vertical strips of each distorted picturebut are magnified horizontally to restore the original proportionsthereof, and that said images as seen through all the lenses combine andblend together in two independent series, seen by the respective eyes,to produce two, independent, composite scenes, each viewable by a singleeye, corresponding portions of said composite scenes beingstereoscopically related.

5. Apparatus according to claim 4 wherein the pictures are taken alongmutually diverging axes, the axes of the lenses being equallyconvergent, the angular divergence between two adjacent axes of thepictures being equal to the angle subtended by the width dimension ofeach lens as measured from the point of convergence of the axes of thelenses. a

6. Apparatus for reproducing on a viewing screen, before an audience,and in stereoscopic relief, a panoramic scene employing a progressiveseries of stereoscopically related pictures adjacent ones of which arestereoscopic t2 doublets, said picture s being taken divergentlyoutwardly toward the panoramic scene, said apparatus comprising: acomposite viewing screen including a horizontal series of contiguousviewing cells compositely arcuate in degree corresponding to the degreeof divergence at which the progressive series of pictures were taken,each viewing cell having a back, projected image receiving projectionurface and a front lens in light communication therewith and spacedtherefrom .a distance less than the focal length of the lens, therespective distances between the individual lenses and their respectiveprojection surfaces being equivalent, and the widths of the respectiveviewing cells being equal; horizontally spaced projector means directedtoward the projection surfaces of said associated cells to cast, solelyupon corresponding ones only of said cells, successive ones of aplurality of pictures taken of said panoramic scene from a regularlydivergent pattern of exposure orientations adjacent ones of whichmutually diverge toward said scene a stereoscopic angle of a magnitudelying within the range of 5" to 4", said front lenses beinganamorphoscopic to magnify horizontally, selected vertical strips ofsaid pictures, selection being determined by the position of theobserver; and means for distorting the vertical-to-horizontal proportionof the pictures prior to casting them onto the projection surfaces tocorn pensate for the horizontal magnification of said lenses, saidlenses being so constructed and so arranged, of them selves and withrespect to their respective, projected image receiving surfaces, thatfrom each viewing angle in the audience there will be seen by therespective eyes of an observer through each front lens respective imageswhich are coextensive in angle subtended with said lens, with respect tosaid respective eyes, and which correspond to adjacent ones of saidnarrow vertical strips of'each distorted picture but are magnifiedhorizontally to restore the original proportions thereof, and that saidimages as seen through all the lenses combine and blend together in twoindependent series, seen by the respective eyes, to produce two,independent, composite scenes, each viewable by .a single eye,corresponding portions of said cornposite scenes being stereoscopicallyrelated.

References Cited hy th-e Examiner UNITED STATES PATENTS JULIA E. COINER,Primary Examiner.

EMIL G. ANDERSON, Examiner,

1. APPARATUS FOR REPRODUCING ON A VIEWING SCREEN, BEFORE AN AUDIENCE,AND IN STEREOSCOPIC RELIEF, A SCENE EMPLOYING A PROGRESSIVE SERIES OFSTEREOSCOPICALLY RELATED PICTURES ADJACENT ONES OF WHICH ARESTEREOSCOPIC DOUBLETS, SAID APPARATUS COMPRISNG: A COMPOSITE CONTIGUOUSVIEWING SCREEN INCLUDING A HORIZONTAL SERIES OF VIEWING CELLS EACHHAVING A BACK, PROJECTED IMAGE RECEIVING PROJECTION SURFACE AND A FRONTLENS IN LIGHT COMMUNICATION THEREWITH AND SPACED THEREFROM A DISTANCELESS THAN THE FOCAL LENGTH OF THE LENS, THE RESPECTIVE DISTANCES BETWEENTHE INDIVIDUAL LENSES AND THEIR RESPECTIVE PROJECTION SURFACES BEINGEQUIVALENT, AND THE WIDTHS OF THE RESPECTIVE VIEWING CELLS BEING EQUAL;A PLURALITY OF HORIZONTALLY SPACED PROJECTOR MEANS EACH DIRECTED SOLELYTOWARD THE PROJECTION SURFACE OF A SINGLE ASSOCIATED CELL TO CASTTHEREON A RESPECTIVE ONE OF A REGULARLY PROGRESSIVE PLURALITY OFPICTURES OF OVERLAPPING SCENE-SECTORS OF A SCENE PHOTOGRAPHED, SAIDFRONT LENSES BEING ANAMORPHOSCOPIC TO MAGNIFY HORIZONTALLY, SELECTEDVERTICAL STRIPS OF SAID PICTURES, SELECTION BEING DETERMINED BY THEPOSITION OF THE OBSERVER; AND MEANS FOR DISTORING THEVERTICAL-TO-HORIZONTAL PROPORTIONS OF THE PICTURES PRIOR TO CASTING THEMONTO THE PROJECTION SURFACES TO COMPENSATE FOR THE HORIZONTALMAGNIFICATION OF SAID LENSES, SAID LENSES BEING SO CONSTRUCTED AND SOARRANGED, OF THEMSELVES AND WITH RESPECT TO THEIR REPECTIVE, PROJECTEDIMAGE RECEIVING PROJECTION SURFACES, THAT FROM EACH VIEWING ANGLE IN THEAUDIENCE THERE WILL BE SEEN BY THE RESPECTIVE EYES OF AN OBSERVERTHROUGH EACH FRONT LENS RESPECTIVE IMAGES WHICH ARE COEXTENSIVE IN ANGLESUBTENDED WITH SAID LENS, WITH RESPECT TO SAID RESPECTIVE EYES, ANDWHICH CORRESPOND TO ADJACENT ONES OF SAID NARROW VERTICAL STRIPS OF EACHDISTORTED PICTURE BUT ARE MAGNIFIED HORIZONTALLY TO RESTORE THE ORIGINALPROPORTIONS THEREOF, AND THAT SAID IMAGES AS SEEN THROUGH ALL THE LENSESCOMBINE AND BLEND TOGETHER IN TWO INDEPENDENT SERIES, SEEN BY THERESPECTIVE EYES, TO PRODUCE TWO, INDEPENDENT, COMPOSITE SCENES, EACHVIEWABLE BY A SINGLE EYE, CORRESPONDING PORTIONS OF SAID COMPOSITESCENES BEING STEREOSCOPICALLY RELATED.